1. Field of the Invention
The present invention relates to a magnetic recording and reproducing apparatus. More particularly, the present invention relates to a simply-structured reel brake device to brake a reel disc on which a tape cassette is mounted, and a magnetic recording and reproducing apparatus having the same.
2. Description of the Related Art
A general magnetic recording and reproducing apparatus comprising a deck mechanism, such as a video cassette recorder (VCR) or a camcorder, records sound and image information using a recording medium, such as a magnetic tape, moving along a predetermined path, and reproduces the recorded information.
The magnetic recording and reproducing apparatus comprises a main chassis having a rotary head drum, a pair of supply reel discs rotatably mounted to the main chassis to drive a tape reel of a tape cassette, a tension unit for generating predetermined tension while the tape cassette is driving and a brake unit for preventing excessive operation of the supply reel disc. The pair of supply reel discs include a supply reel disc for supplying a tape and a take-up reel disc for rewinding the tape being untied from the supply reel disc. Since the take-up reel disc is not an essential element of the present invention, a detailed description thereof will be ommitted.
FIG. 1 shows a tension unit 10 mounted to a main chassis (not shown), a supply reel disc 30 rotated by the tension unit 10 and a brake unit 50 rotatably mounted to the main chassis (not shown) to selectively brake the supply reel disc 30.
The tension unit 10 comprises a tension arm 12 pivotably mounted on the main chassis, a tension pole 14 formed at one end of the tension arm 12 to withdraw a magnetic tape 22 from a tape cassette and a tension band 16 mounted to the tension arm 12 to enclose an outer periphery of the supply reel disc 30. The supply reel disc 30 has a reel gear 32, at a lower part thereof, rotated by a power transmitted from a capstan motor (not shown).
The brake unit 50 is pivotably mounted on the main chassis to selectively brake the supply reel disc 30. The brake unit 50 comprises a sub brake 52, a main brake 54, a coil spring 56 and a torsion spring 58. The sub brake 52 is pivotably mounted on the main chassis so that one end thereof selectively biases the tension band 16 to the supply reel disc 30. The main brake 54, which is coaxial with the sub brake 52, is pivotably mounted on the main chassis to selectively lock and release the supply reel disc 30. The coil spring 56 elastically pushes the sub brake 52 in contact with the supply reel disc 30. The torsion spring 58 is disposed between the sub brake 52 and the main brake 54 to elastically push the main brake 54 so that the main brake 54 is contacted with the reel gear 32.
A dotted line in FIG. 1 shows the tension unit 10 in a state that a tape cassette is loaded in a magnetic recording and reproducing apparatus. When the tape cassette is loaded, the tension arm 12 rotates about an axis 18 in association with a cam gear (not shown) which is driven by a driving motor (not shown) in a direction illustrated by an arrow. Therefore, the tension pole 14 provided at an end of the tension arm 12 and a pole base unit 20 withdraw the magnetic tape 22 from the tape cassette. The magnetic tape 22 being withdrawn rotates the reel (not shown) of the tape cassette, and the reel of the tape cassette rotates the supply reel disc 30. Due to rotation inertia of the supply reel disc 30, the magnetic tape 22 may be excessively withdrawn even after the tape cassette is loaded. To avoid this, the tension band 16 is provided on the outer periphery of the supply reel disc 30. The sub brake 52 pushes the tension band 16, thereby applying a predetermined friction to the supply reel disc 30. By the friction, the supply reel disc 30 is prevented from being rotated after loading the tape cassette. In addition, the main brake 54 is connected and locked to the reel gear 32 mounted at the lower part of the supply reel disc 30 in order to prevent the tape from being withdrawn continuously by the rotation inertia of the supply reel disc 30 when a play mode is converted to a stop mode.
However, as can be appreciated from the above, the brake unit 50 requires a number of parts and has a complicated structure, thereby increasing manufacturing steps. Accordingly, manufacturing cost and a size of the apparatus are also increased. Therefore, research has been directed to minimizing the size of the apparatus and saving manufacturing costs.